California Governor Jerry Brown and Mexican environmental officials signed a pact on Monday aimed at reducing greenhouse gas emissions, an agreement that could eventually expand the market for carbon credits.

The six-page memorandum of understanding calls for cooperation in developing carbon pricing systems and calls on the partners to explore ways to align those systems in the future.

Curbing climate change is profitable and nations must offer business incentives for low-carbon growth to cut fossil-fuel reliance, according to former president of Mexico, Felipe Calderon.

Countries must act jointly and in a “comprehensive” way, targeting the energy industry, cities, agriculture and forests as the main areas where runaway greenhouse gas emissions can be reined in, Calderon said in an interview in London. The former leader is now chairman of the Global Commission on the Economy and Climate, a panel set up by seven nations including the U.K. to advise on the best ways to tackle global warming.

Hundreds of parliamentarians from around the world will gather in Mexico this weekend to sign a new blueprint that aims to stop average global temperatures rising to two degrees celsius above pre-industrial levels.

The World Summit of Legislators, organised by Globe International, comes in the same week that the world’s two largest emitters- the USA and China – signaled major new plans to curb carbon dioxide emissions over the coming decades.

It’s been a tough spring for Cinco de Mayo fans and the bars that keep them plied with tart margaritas, as the Great Lime Shortage of 2014 has been threatening to break up the party. Cocktail prices spiked, bars passed off lemons as substitutes, and a 40-pound carton of limes shot past $100 in the United States, four times the normal price.

Nearly all the limes thumbed into Corona bottles come from Mexico, amounting to a half million tons of U.S. imports. And there have been many theories about what caused the unusual prices, including that the cost of extortion by drug cartels in the lime-growing state of Michoacan was being passed on to customers north of the border.

But Mexican lime growers attribute the high prices to something more mundane: bad weather. Unusually heavy rains last winter led to an outbreak of a fungus that destroyed many lime trees and reduced the national supply. “It’s climate change,” said Enrique Saavedra, director general of B&S Grupo Exportador, a lime supplier in Veracruz, the Mexican state sending the most limes to the United States. “People speculate that it had something to do with security in Michoacan, but it wasn’t that.”

Former Mexican President Felipe Calderon is spearheading a study sponsored by seven countries into the economics of climate change, seeking to elucidate the financial benefits of reducing carbon emissions. Calderon’s panel will draw from the experiences of companies and governments around the world in fighting off the ravages of storms and droughts, and in cutting greenhouse gases. It also will use academic research to show the costs and risks associated with climate change and efforts to stem it, publishing a report next September to guide policy makers.

Mexico’s famous beach resort of Acapulco was in chaos on Tuesday as hotels rationed food for thousands of stranded tourists and floodwaters swallowed homes and cars after some of the most damaging storms in decades killed at least 55 people across the country.

Television footage showed Acapulco’s international airport terminal waist deep in water and workers wading out to escape floods that have prevented some 40,000 visitors from leaving and blocked one of the main access routes to the city with mud.

Since the 1980s, the Mexican government has subsidized massive tract-housing projects around the country, filling them with hundreds of thousands of concrete-block, brick and mortar structures that have no insulation or other comfort control features. This response to intense pressure for affordable urban housing is to blame for widespread urban sprawl in Mexico over the last 30 years – and increases in climate-changing emissions, experts say. Homes now use 16 percent of the country’s energy and account for 3 percent of direct greenhouse gas emissions, as well as a variety of indirect ones, according to the country’s Social Development Ministry.

That rising urban carbon footprint is one reason the country’s climate change policymakers see cutting residential emissions as essential for reaching Mexico’s 2050 target to cut its greenhouse gas emissions in half from 2002 levels. To accomplish the needed cut, they have turned to a so-called Eco House program, which Gisela Campillo Bermudo, leader of the Inter-American Development Bank’s infrastructure and environment team, says is new in Latin America.